Carb help?

[Slugboy2]

Gentlemen,
I have a 1990 CR500R, as seen in the steelie forum a while back. Can somebody explain how the idle adjustment/choke knob thingamabob works? The bike runs great, but won't idle. I cant get a response from turning the choke knob in either direction.
Thanx in advance.
Slugboy

[AlisoBob]

Turning the knob adjusts the idle speed.

The pilot jet and airscrew setting adjust idle quality.

Big difference....

[CR500PHIL]

Gentlemen,
I have a 1990 CR500R, as seen in the steelie forum a while back. Can somebody explain how the idle adjustment/choke knob thingamabob works? The bike runs great, but won't idle. I cant get a response from turning the choke knob in either direction.
Thanx in advance.
Slugboy

If your idle adjustment has no effect your jetting is perhaps off. The pilot jet effects the idle since it is the same circuit for a PJ carb. I had the same problem with an AF I built. I went from a 55 pilot to eventually a 48 and instantly the idle adjustment worked perfectly. Don't listen to people who say CR500s won't idle with a PJ - both I had idled perfectly once jetted properly. There are lots of good jetting help on here. Bab has a some real good stickies on the subject as well. Good luck.

[Slugboy2]

Thanks Phil. I went to the 48 pilot and it idles perfect. Thanks for takin' the time...

[CR500PHIL]

Thanks Phil. I went to the 48 pilot and it idles perfect. Thanks for takin' the time...

No problem I am glad it worked out for you.

[86500]

im thinking my pilot is too large and soaking the plug on kick, lets go see

[lms1977]

My motor is a 87 it is suppose to have a 55 pilot but plug is black I will switch back to the 52 pilot which the plug looked much better both idled ok and ran similar

[CR500PHIL]

My motor is a 87 it is suppose to have a 55 pilot but plug is black I will switch back to the 52 pilot which the plug looked much better both idled ok and ran similar

Stock jetting is a starting point - many factors impact jetting. The best way to get it as good as possible is to learn to read the signs ie. surge means lean etc. I have mine about as close as possible now but it did not happen without some trial and error and a lot of learning. I must re-interate the worth of Bob's sticky on jetting - it helped me tremendously. My bike will now start in 1 to 2 kicks cold (if you kick it like a mule), idles perfectly, pulls like a jet and never fouls plugs.